Table 4 Power calculation for changes in practice for various assumptions of % with practice pre-intervention – p1(20–60%), p2 (30–90%), assuming 80% power at 5% level of statistical significance (2-sided test), for sizes of effect ≤ 2 and for cluster size six (numbers of annual live births per hospital)
| ICC assumption required for 780 babies | ||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| p 1 | P 2 | |||||||||||||
| 30 | 35 | 40 | 45 | 50 | 55 | 60 | 65 | 70 | 75 | 80 | 85 | 90 | ||
| 60 | 0.02 | 0.31 | ||||||||||||
| 55 | 0.28 | |||||||||||||
| 50 | 0.26 | |||||||||||||
| 45 | 0.25 | 0.6 | ||||||||||||
| 40 | 0.25 | 0.6 | ||||||||||||
| 35 | 0.01 | 0.26 | 0.6 | |||||||||||
| 30 | 0.02 | 0.28 | ||||||||||||
| 25 | 0.04 | 0.31 | ||||||||||||
| 20 | 0.06 | 0.36 | ||||||||||||